It's insane to imagine Lyndon Johnson living into the 2000s. If he outlived Lady Bird, he could very well have seen Obama's election.
He would have been 100 years old at that time. So possible, but not likely. JKF on the other hand would have been 91 in 2008 if he had lived.
I always remember a scene from the movie Path to War where LBJ (Michael Gambon) is talking to George Wallace (Gary Sinise) about their legacies and not thinking about 1965/66 but about 1995/96. They would be long gone and in their graves but what they did on that day would matter.
LBJ never came close but Wallace lived to 1998.